Inversion of GPS occultation measurements using Fresnel diffraction theory

Occultation data from the GPS/MET experiment are inverted to temperature profiles of the neutral atmosphere of the Earth using the Fresnel inversion technique. The technique is not limited in resolution by diffraction effects thus a good vertical resolution is achieved. In the derivation a thin screen approximation is used. The influence of this approximation on the results is discussed. The results obtained using the Fresnel inversion is compared to results obtained using the traditional geometrical optics inversion approach and to numerical weather prediction data.